Nick Kyrgios risks a heavy fine after going into a sulk and appearing to stop trying during his Wimbledon fourth-round defeat against Richard Gasquet.

The 20-year-old Australian downed tools early in the second set of the clash on Court Two, where he also was given a ticking-off for swearing and rowed with British umpire James Keothavong over a change of socks.

It was the code violation for an "audible obscenity" that seemed to spark the petulance from Kyrgios, who was heading a break down when Keothavong warned him over his coarse language.

In an act of ill-advised rebellion, in the third game of the second set, Kyrgios let two serves slide by him for aces without even swinging his racquet.

He meekly fed back two further Gasquet serves into the net in a game of complete surrender.

Kyrgios was booed by hundreds of fans who felt short-changed by his lack of effort and it barely improved as he gave up the set in just 24 minutes.

Despite picking up his performance thereafter, Kyrgios went on to lose the match 7-5 6-1 6-7 (7/9) 7-6 (8/6).

Kyrgios told reporters that he feels "misunderstood" and brushed aside the boos he heard from the crowd, saying they had cheered him later in the match.

He admitted that following the code violation he had responded with "frustration" but appeared to deny that he had thrown a game, claiming: "Of course I tried."

His childish attitude could bring with it a cost. International Tennis Federation rules state: "A player shall use his best efforts to win a match when competing in a grand slam tournament. Violation of this section shall subject a player to a fine up to 20,000 US dollars (£12,860) for each violation."

Additionally, the rules state: "In circumstances that are flagrant and particularly injurious to the success of a tournament, or are singularly egregious, a single violation ... shall also constitute the major offence of 'aggravated behaviour' and shall be subject to the additional penalties hereinafter set forth therefor." That allows the ITF to impose a penalty of 250,000 US dollars (£160,000).

Gasquet himself smashed his racquet after the third set, crunching it into the grass and then smashing it against his chair in frustration after letting two match points slip by.

The third set also saw Kyrgios and Keothavong involved in a bizarre exchange over the Australian adjusting his kit.

"I'm changing my socks," Kyrgios explained to Keothavong at the changeover following the third game.

"I've taken one pair off. I've got two on and I'm taking one pair off." After Keothavong replied to Kyrgios, the combustible Canberra man said: "I'm staying on the court.

"If you're going to get angry with me for that, that's another level.

"Mate, Rafa (Rafael Nadal) and stuff play 30 seconds in between points every time and all I'm doing is putting my sock back on."

Referring to Gasquet, Kyrgios said: "I'm sure he'll understand.

"Do you wanna ask him?"

Kyrgios then shouted from his chair to Gasquet on court: "Richard, I'm just changing my socks."